Boat construction



United States Patent 3,09,24l BQAT CUNSTRUCTEGN Charles A. Montague,Jr., 5269 Pecan Grove Lane, Memphis 17, Tenn. Filed May 24, 1961, filer.No. 112,443 13 Claims. (Cl. 1l4o6.5)

This invention relates to improvements in boats and more particularly tomeans for rapidly accelerating such boats.

One of the primary objects of the present invention is to provide a boatthat is capable of obtaining rapid acceleration.

A [further object is to obtain acceleration of the boat with less powerthan is required by conventional arrangements.

A further object is to provide means in a boat to lift the boat duringthe initial phases of the operation of the propeller and before the boatbegins to move through the water, so that rapid acceleration may beobtained.

A further object is to obtain lift regardless of the acceleration of theboat through the utilization of the velocity imparted to the water bythe propeller acting on the lifting device of the present invention.

A further object is to increase the load starting and towing capacity ofa heat.

A further object is to decrease the wake formed by a boat, whichotherwise would be hazardous to water skiing, fishing and boat riding.

A further object is to increase the overall efiiciency of a boat byobtaining power use while decreasing the power lost due to reducing thedisplaced volume of water.

A [further object is to utilize the lift obtained by the presentinvention to improve the boats attitude in the water during starting andrunning.

A (further object is to provide a boat which is particularly useful forhigh-speed patrol craft, military attack craft, rescue boats, racing,sporting boats, high-speed ferries and other uses in which rapidacceleration is required or desired.

A further object is to provide a boat which is capable of furnishingimmediate power starting from standstill that is necessary in pullingwater skiers.

A further object is to provide an attachment for boat motors which willcause the boat to which the motor is attached to rise in the water,thereby reducing the displacement area of the boat, to improve theattitude of the boat in the water and thereby to provide rapidacceleration and other advantages.

Other and further objects and advantages of the present invention willbe apparent from the specification hereinafter set forth and the novelfeatures thereof defined in the appended claims.

The means by which the foregoing and other objects of the presentinvention are accomplished and the manner of their accomplishment willbe readily understood from the following specification upon reference tothe accompanying drawings, in which:

FIG. 1 is a plan view of the boat construction of the present invention.

FIG. 2 is a side elevational view thereof with parts broken away forpurposes of illustration.

FIG. 3 is an enlarged side elevational view of the attachment of thepresent invention shown attached to an outboard motor, with only afragmentary lower portion of the outboard motor being shown.

FIG. 4 is an end elevational view of the device shown in FIG. 3 with apart broken away for purposes of illust-ration.

FIG. 5 is a sectional view taken as on the line VV of FIG. 4.

ice

FIG. 6 is a plan view of the attachment itself.

FIG. 7 is a sectional view taken as on the line VIIVII of FIG. 4 of apreferred form of the present invention.

FIG. 8 is a view similar to FIG. 7 of an alternate form of the presentinvention.

FIG. 9 is a view similar to FIG. 7 of still another alternate form ofthe present invention.

Referring now to the drawings in which the various parts are indicatedby numerals, FIGS. 1 and 2 of the drawings show a boat 11 employing thepresent invention wherein it will be seen a plurality of propellingunits 13 are shown attached to hull 15 of boat 11. Propelling units 13are preferably though not necessarily, three in number and preferablylocated so that when the propelling units cause a lift, as will be laterdescribed, the upward lift will be transmitted to the boat 11 in asubstantially balanced manner. Thus, a propelling unit 13 is preferablyattached on each side of boat 11 intermediate the ends thereof. Thepropelling units 13 on the sides of the boat are attached by anysuitable means, as braces 17. In addition, a propelling unit 13 isattached adjacent the stern of the boat 11 in the usual manner so thatthe propelling unit is pivotable about a substantially vertical axis tosteer the boat, as by means of the usual handle 19. The propelling units13 are preferably centrally controlled as by a conventional remote gearshift and throttle control as at 20. Each propelling unit 13 issubstantially the same in construction, and the following descriptionfor one will sufiice for all.

Each unit 13 preferably comprises the usual propelling means including amotor 21, having the usual housing 23 depending therefrom to which ismounted adjacent the lower end thereof the usual gear box 25. Inaddition, the usual propeller 27 is rotatably mounted from gear box 25for drive by motor 21, and the usual propeller guard 29 depends fromgear box 25 to protect propeller 27. Although an outboard propellingunit 13 is illustrated in the drawings, it will be understood that aninboard propelling unit or the like may be provided without departingfrom the spirit and scope of the present invention Each of propellingunits 13 includes a lifting device 31 of the present invention, whichlifting device is located below the lower portion of propeller 27 andarranged in such a manner that when the propeller is rotated -a flow ofwater will be accelerated through the lifting device.

Lifting device 31 comprises in general a substantially vertical post 33,a rearward portion 35 and a narrow lower neck portion 37 rigidly andintegrally interconnecting the post and the rearward portion. Rearwardportion 35 is in the form of a generally channebshaped member andincludes 'a pair of upwardly curved wing portions 39 which extendupwardly on opposite sides of propeller 27 in closely spacedrelationship thereto and terminate substantially level with themid-point of the propeller. When viewed from the rear, as in FIG. 4,rearward portion 35 forms substantially a semi-circle of a greaterdiameter than the circular path of propeller 27. The forward side edges41 of rearward portion 35 lead upwardly and outwardly from lower neckportion 3-7 to the circular rearward edge 43 of the rearward portion. Inother words, rearward portion 35 may be thought of as being formed fromthe lower half of a hollow and substantially cylindrical piece with theaxis of the cylinder extending horizontally in substantial coincidencewith the axis of rotation of propeller 27 and with portions of thecylinder being cut away on opposite sides thereof along :arcuate linesextending from adjacent neck portion 37 outwardly and upwardly torearward edge 43 to establish edges 41.

Means is provided for attaching lifting device 31 so that it is locatedbelow propeller 27, as heretofore described, and this means preferablycomprises a cap 45.

Cap 45 is adapted to fit around the lower portion 47 of gear box 25 andaround propeller guard 2% in spaced relationship to the portion 47 andguard 29 with a rubber fill 49 or the like being provided therebetweento establish a firm connection. In other words, cap 45 is in the samegeneral configuration as portion 47 and guard 29 but larger so that theportion and the guard are adapted to fit into the cap with a voidtherebetween which is filled with rubber or the like. The rearward endwall 51 of cap 45 is even with the rearward end of gear box 25 andextends thereto. Cap 45 is preferably held in place by means of screws53, which are preferably the same screws that normally hold the lowerportion 47 of the gear box to the remainder of the gear box. Therearward portion of cap 45 is preferably flat as at 55 to receive inflat face-to-face engagement the forward face 57 of post 33, which postis firmly anchored to the cap by means of bolts 59 extending throughbores 61 provided in the post and threadedly engaged in threaded sockets63 respectively aligned with bores 61. If desired, cap 45 may be omittedand the post 33 attached directly to guard 29, as by bolts or the like,without departing from the spirit and scope of the present invention.

Boat 11 is preferably provided with a stabilizing device 65 whichincludes a vane 67 pivotally supported below hull 15 for pivot about ahorizontal axis, as by means of struts 69 attached to the bottom of boat11 and depending therefrom and connected to vane 67 by a pivot axle 7.1.A link 73 is pivotally attached to vane 67 adjacent the rearward endthereof as at 75. Link 73 slidably extends upwardly through a bore 77 inboat 11, which is provided with suitable sealing means to prevent waterfrom entering the boat. The upper end of link 73 is pivotally attachedto one end of a crank lever 79 as at 81. Crank lever 79 is pivotallymounted zfrom the inside of bull 15 as at 83 and bears against suitablewell-known notched means 85 so that the crank lever can be moved butwill remain in the position into which moved. A knob 87 is provided oncrank lever 79 so that the crank lever can be pivoted to move link 73 upand down which in turn will pivot vane 67, whereby the vane may be movedto a desired position for stabilizing and adjusting the attitude and thedepth of the vane 67 in thewater.

In describing the operation of boat 11, it is assumed that the boat isat a standstill with the propelling units in an idling disposition, thatis, with propellers 27 either stopped or slowly revolving. Then, whenpropellers 27 are accelerated a high velocity of water will be caused topass through lifting device 31, which high velocity is in contrast tothe low or zero velocity of water around the outside of lifting device31. It will be understood that with this difference in the velocitiesthere will be a littt imparted to lifting device 31 which in turn willbe transmitted to boat 11 through the propelling units 13 so that priorto and during the actual movement 01f the boat through the water, theboat will be lifted upwardly and there will be less displacement of thewater by the hull with a more rapid acceleration of the boat beingpermitted. Thus, it will be seen that a degree of lift is generated whenpropellers 27 are rotated regardless of the movement of the propelledboat 11. This lift is due to the relative velocities described whichresult from [the propelling of water through the lifting device 31 priorto the boat 11 obtaining its speed. As the boat 11 gains speed, therelative velocities of the water inside of device 31 and outside of thedevice may increase or decrease depending upon the horsepower requiredto accelerate and maintain the speed of the boat at various speeds andattitudes in the water. Consequently, this lift will vary with theactual slippage of the water about the projected circumference of thepropeller which results. If it is desired to increase the lift abovethat caused by slippage, this is done by using a hydrofoil section, asin the preferred section shown in FIG. 7, which will generate adifference in water velocity above and below lifting device 31 caused bythe absolute speed of boat 11. This difference in velocity will becaused by the fact that the water allowing over the curved upper surface57 of the hydrofoil section has to travel a greater distance than thewater flowing under the straight lower surface 59 of the hydrofoilsection. However, if it is desired to decrease the lift resulting fromthe slippage, a reverse or upsidedown hydrofoil section, as shown inFIG. 8, may be employed, which has a straight upper surface 61 and alonger curved lower surface 63. In addition, if it is desired to equalthe lift resulting from the slippage at various speeds, a streamlinedsection, as shown in FIG. 9, can be used, where the upper and lowercurved surfaces 65, 67 are substantially equal in distance. In otherwords, various effects may be had by a variation of the section from afoil section to a more nearly streamlined or streamlined section and toa reverse foil section. It will be understood that the overall efiect oflifting device 31 will 'be to cause a lifting force to be exertedregardless of the shape of the foil section, and that the foil sectionwill only affect the degree of the lift.

It will be understood that stabilizing device 65 is useful instabilizing boat 11, or changing the trim thereof.

From the foregoing description it will be apparent that a boat 11 isprovided which is adapted to have rapid acceleration from a start deadin the water to full speed. In addition, it will be understood that sucha boat is provided which offers many advantages to boats attempting tostart towed loads, such as boats pulling water skiers, or for rescuevessels which would need to have a rapid acceleration. Other usefulapplications would be for high-speed patrol craft, military attackcraft, bigh-speed ferries and racing boats. It will be understood thatwhen multiple propelling units 13 are used, this allows the entirepropelled boat to be lifted from the water by the lifting devices 31immediately upon acceleration of the propellers. However, it will beunderstood that, if desired, only a single propelling unit 13 need beused, as .for example, in a motor boat to pull water skiers. In thislatter event the improved load starting and acceleration characteristicswould be gained primarily from the improved attitude of the boat in thewater resulting from the lift provided by subject invention. This liftwould act to overcome the heavy weight of the motor on the rear of theboat and the undesired rotational movement exerted on the boat by thethrust of the motor, both of which tend to impair the attitude of theboat in the water, particularly upon initial acceleration.

Although the invention has been described in some detail by way ofillustration and example for purposes of clarity or understanding, it isto be understood that changes and modifications may be made thereinwhich are within the dull intended scope of this invention ashereinaflter claimed.

I claim:

1. A boat comprising a hull, a plurality of spaced propelling unitsattached to said :hull for the propelling thereof, said propelling unitsincluding propellers rotatably mounted for rotation about substantiallyhorizontal axes, means for rotatably driving said propellers, aplurality of channel-shaped members, each of said channel-shaped membersbeing of substantially the shape of a portion of a hollow cylinder andhaving a substantially horizontal axis, said channel-shaped membersbeing respectively mounted substantially below said propellers with theaxes thereof being respectively substantially coincident with the axesof rotation of said propellers and with said channel-shaped membersextending upwardly on opposite sides of said propellers to places oftermination substantially at a level with the middle of said propellersso that said channel-shaped members respectively substantially surroundthe lower halves of the path of rotation of said propellers in closelyspaced relationship thereto, whereby the flow of water from saidpropellers respectively over said channel-shaped members causes anupward lift of said hull, and adjustable vane means supported from saidhull and extending therebelow for adjusting the attitude of said boat.

2. A boat comprising a hull, a plurality of spaced propelling unitsattached to said hull for the propelling thereof, said propelling unitsincluding propellers rotatably mounted for rotation about substantiallyhorizontal axes, means for rotatably driving said propellers, aplurality of channel-shaped members, each of said channelshaped membersbeing of substantially the shape of a portion of a hollow cylinder andhaving a substantially horizontal axis, said channel-shaped membersbeing respectively mounted substantially below said propellers with theaxes thereof being respectively substantially coincident with the axesof rotation of said propellers and with said channel-shaped membersextending upwardly on opposite sides of said propellers to places oftermination substantially at a level with the middle of said propellersso that said channel-shaped members respectively substantially surroundthe lower halves of the path of rotation of said propellers in closelyspaced relationship thereto, whereby the flow of water from saidpropellers respectively over said channel-shaped members causes anupward lift of said hull.

3. A boat comprising a hull, at least one propelling unit attached tosaid hull for the propelling thereof, said propelling unit including apropeller with said propeller being unobstructed over the top of thepath of rotation thereof, means for rotatably driving said propeller tocause a rearward flow of water from said propeller, a channel-shapedmember, said channel-shaped member being mounted on said propelling unitin such a position that the rearward flow of water from said propellerpasses over said channel-shaped member to cause an upward lift thereon.

4. In a boat having at least one propelling unit adjacent the rearwardend thereof with said propelling unit including a rotatably drivenpropeller for establishing a rearward flow of water and with saidpropeller being unobstructed over the top of the path of rotationthereof, means for causing a lifting force to be exerted on said boat atsaid propelling unit comprising a channel-shaped member including a pairof wings, said channel-shaped member being attached to said propellingunit and mounted so that the rearward how of water from said propellerpasses over said channel-shaped member to cause an upward lift thereon.

5. The structure according to claim 1 in which the cross-section of saidchannel-shaped member is in the shape of a hydrofoil having a straightlower surface and a longer curved upper surface.

6. The structure according to claim 1 in which the cross-section of saidchannel-shaped member is in the shape of a reverse hydrofoil having astraight upper surface and a longer curved lower surface.

7. The structure according to claim 1 in which the cross-section of saidchannel-shaped member is in a streamlined shape having upper and lowercurved surfaces of substantially equal distances therearound.

8. The structure according to claim 4 in which (the cross-section ofsaid channel-shaped member is in the shape of a hydrofoil having astraight lower surface and a longer curved upper surface.

9. The structure according to claim 4 in which the cross-section of saidchannel-shaped member is in the shape of a reverse hydrofoil having astraight upper surface and a longer curved lower surface.

10. In a boat having at least one propelling unit ineluding a propellerguard and a rotatably driven propeller having a substantially horizontalaxis of rotation with said propeller being unobstructed over the top ofthe path of rotation thereof, an attachment for said propelling unitcomprising a cap, a post, means rigidly connecting said cap and saidpost, a channel-shaped member of substantially the shape of a portion ofa hollow cylinder, a narrow neck portion integrally interconnecting saidpost and said channel-shaped member, said channelshaped member having asubstantially semi-circular rearward edge and having opposite side edgesextending arcuately upwardly and outwardly from said narrow neck portionto said rearward edge, said cap being disposed over said guard with aspace therebetween, a resilient fill in the space between said guard andsaid cap, and means attaching said cap to said propelling unit tosupport said channel-shaped member below said propeller, saidchannel-shaped member surrounding the lower half of the path of rotationof said propeller.

11. An attachment for a propelling unit having a rotatably drivenpropeller and a propeller guard adjacent thereto, said attachmentcomprising a cap, a post, means rigidly connecting said cap and saidpost, a channelshaped member of substantially the shape of a portion ofa hollow cylinder, a narrow neck portion integrally interconnecting saidpost and said channel-shaped member, said channel-shaped member having asubstantially semi-circular rearward edge and having opposite side edgesextending upwardly and outwardly from said narrow neck portion to saidrearward edge, said cap being of a shape to fit over said guard forattachment thereto to support said channel-shaped member below saidpropeller.

12. An attachment for a propelling unit of the outboard motor typehaving a rotatably driven propeller unobstructed over the top of thepath of rotation thereof, said attachment comprising a post, achannel-shaped member including a pair of wings arranged in asemicircular arc for enclosing the lower half of the path of rotation ofsaid propeller, a narrow neck portion integrally interconnecting saidpost and said channel-shaped member, and means attached to said post forconnecting said attachment to a propelling unit to support saidchannel-shaped member substantially below the propeller of thepropelling unit to which attached.

13. In a boat having at least one propelling unit pivotally mountedadjacent the rearward end thereof for pivot about a substantiallyvertical axis to guide the boat and with said propel-ling unit includinga rotatably driven propeller for establishing a rearward flow of water,said propeller being unobstructed over the top of the path of rotationrthereof, means for causing a lifting force to be exerted on said boatat said propelling unit comprising a channel-shaped member including apair of wings, said channel-shaped member being attached to saidpropelling unit and mounted so that the rearward fiow of water from saidpropeller passes over said channel-shaped member to cause an upward liftthereon, said wings being closely adjacent to said propeller andenclosing the lower half of the path of rotation of said propeller, andsaid channel-shaped member being movable with said propelling unit whensaid propelling unit is pivoted to turn said boat.

References Cited in the file of this patent UNITED STATES PATENTS804,497 Palmer Nov. 14, 1905 806,484 Palmer Dec. 5, 1905 985,187Lindgren Feb. 28, 1911 1,976,046 Tietjens Oct. 9, 1934 2,274,200 HillFeb. 24, 1942 2,749,870 Vavra June 12, 1956 2,773,467 Bailey Dec. 11,1956 2,985,133 Shaffer May 23, 1961 FOREIGN PATENTS 147,473 Sweden Oct.26, 1954

1. A BOAT COMPRISING A HULL, A PLURALITY OF SPACED PROPELLING UNITSATTACHED TO SAID HULL FOR THE PROPELLING THEREOF, SAID PROPELLING UNITSINCLUDING PROPELLERS ROTATABLY MOUNTED FOR ROTATION ABOUT SUBSTANTIALLYHORIZONTAL AXES, MEANS FOR ROTATABLY DRIVING SID PROPELLERS, A PLURALITYOF CHANNEL-SHAPED MEMBERS, EACH OF SAID CHANNEL-SHAPED MEMBERS BEING OFSUBSTANTIALLY THE SHAPE OF A PORTION OF A HOLLOW CYLINDER AND HAVING ASUBSTANTIALLY HORIZONTAL AXIS, SAID CHANNEL-SHAPED MEMBERS BEINGRESPECTIVELY MOUNTED SUBSTANTIALLY BELOW SAID PROPELLERS WITH THE AXESTHEREOF BEING RESPECTIVELY SUBSTANTIALLY COINCIDENT WITH THE AXES OFROTAWTION OF SAID PROPELLERS AND WITH SAID CHANNEL-SHAPED MEMBERSEXTENDING UPWARDLY ON OPPOSITE SIDES OF SAID PROPELLERS TO PLACE OFTERMINATION SUBSTANTIALLY AT A LEVEL WITH THE MIDDLE OF SAID PROPELLERSSO THAT SAID CHANNEL-SHAPED MEMBERS RESPECTIVELY SUBSTANTTIALY SURROUNDTHE LOWER HALVES OF THE PATH OF ROTATION OF SAID PROPELLERS IN CLOSELYSPACED RELATIONSHIP THERETO, WHEREBY THE FLOW OF WATER FROM SAIDPROPELLERS RESPECTIVELY OVER SAID CHANNEL-SHAPED MEMBERS CAUSES ANUPWARD LIFT OF SAID HULL, AND ADJUSTABLE VANE MEANS SUPPORTED FROM SAIDHULL AND EXTENDING THEREBELOW FOR ADJUSTING THE ATTITUDE OF SAID BOAT,